Ceramic tiles

ABSTRACT

The specification describes improved ceramic &#39;&#39;&#39;&#39;split&#39;&#39;&#39;&#39; tiles, that is to say tiles which are joined together back to back during firing and split apart for use. In accordance with the invention, the tiles of each pair are connected together by connecting zones or necks alternating with raised or convex and sunken or concave surface portions. The raised and sunken surface portions are present on both tiles and each raised surface portion fits in a complementary manner into a sunken portion in the other tile and stands proud of the connecting zones.

Unite States atent 91 Mrasek 1 1 Mar. 25, 1975 1 1 CERAMIC TILES [75] Inventor: Karl Mrasek, Schwarzenfeld,

Germany 1731 Assigneez Buchtal GmbH, Schwarzenfeld,

Germany [22] Filed: Feb. 22, 1973 [21] App]. No.: 334,638

[30] Foreign Application Priority Data Mar. 10, 1972 Germany 2211747 1,534,353 4/1925 Besser 52/98 1,884,822 10/1932 Parker 52/100 2,291,974 8/1942 Miller ct a1. 52/98 3,354,592 11/1967 Curci 52/98 3,461,196 8/1969 Bowles 264/157 FOREIGN PATENTS OR APPLICATIONS 298.109 6/1932 Italy 52/98 Primary Examiner-George F. Lesmes Assistant Examiner-R. J. Roche Attorney, Agent, or Firm-Price, Heneveld, Huizenga & Cooper [57] ABSTRACT The specification describes improved ceramic split tiles, that is to say tiles which are joined together back to back during firing and split apart for use. In accordance with the invention, the tiles of each pair are connected together by connecting zones or necks alternating with raised or convex and sunken or concave [56] References Cited surface portions. The raised and sunken surface por- UNITED STATES PATENTS tions are present on both tiles and each raised surface 402,897 5/1889 Breed 404/39 portion tits in a complementary manner into a sunken 4201731 2/1890 P319811 portion in the other tile and stands proud of the con- Marvin... necting ones 923,921 6/1909 Wise 989,677 4/191 1 Wiedenholdt 52/100 8 Claims, 5 Drawing Figures 6 1 I 1 I. 1 11 '11 [11 [11 1| /n 11 111 1'1- l 1 l.

CERAMIC TILES BACKGROUND OF THE INVENTION The invention relates to split tiles for covering or cladding purposes and made of densely fired ceramic material, and more particularly to such split tiles which have convex or raised and concave or sunken portions on the backside which run parallel to each other adapted to serve as interlocking anchoring means for the tile when mounted or installed on a bed of mortar or other adhesive material applied to the surface to be clad.

In accordance with a prior proposal (see German patent specification No. 1,659,587) a split tile or flag for cladding purposes and consisting of densely fired ceramic material was provided with projections in the form of parallel members on the rear side or surface for the purpose of anchoring the tile or flag by a mortar bed on the surface to be tiled. These projections were in the form of ribs running in the longitudinal direction of the tile.

In the case of this previously proposed split tile or flag, the ribs were arranged in groups inclined alternately to both sides and were provided with connecting pieces which connected the two tiles together. The connecting pieces were arranged between the groups of ribs and had a rhombic cross section. The thinnest part of the rhombic cross sections of the connecting pieces were located adjacent to the rear side of the respective tile.

The purpose of this construction was to ensure that at the connecting pieces, after separation or splitting of the pair of split tiles, no rough broken edges or flash remained projecting beyond the maximum height of the ribs.

These tiles were found satisfactory but on splitting a pair of split tiles to form the individual split tiles, the connecting pieces dropped off in the form of thin pins or beaks which have to be cleaned up or swept away by the operator. Furthermore, due to the use of such connecting pieces, the spacing between the rear sides of the two split tiles in the pair necessarily was comparatively large so that the tile occupied a comparatively large amount of space while drying and firing in a tunnel kiln.

SUMMARY OF THE INVENTION One aim of the present invention is to improve split tiles in such a manner that on splitting no debris is produced and on the other hand, it is possible to ensure that the transverse or thickness dimensions of the pair of tiles is minimal so that the space available in the kiln for drying and firing is used to an optimum extent. In accordance with a further aspect of the invention, it is naturally necessary to ensure that any broken edges of flash at the site of fracture or tile separation does not extend above the maximum height of the anchoring ribs. Furthermore, another object of the invention is to keep the cavities at the rear side of the tiles or flags as small as possible in order to minimize the amount of mortar or other adhesive used in laying.

The present invention consists of a tile for cladding purposes, made of densely fired ceramic material, and more particularly to such, split tiles which have raised, convex portions on the backside which run parallel to each other and adapted to serve as interlocking, anchoring means for the tile on a bed of mortar or other adhesive material applied to the surface to be clad, characterised in that the tiles of the pair of split tiles have on their rear sides of faces interconnected recesses which extend in the longitudinal direction of the tile and which are separated by connecting parts also extending in the longitudinal direction of the tile, which result in mutually complementary raised or convex portions and sunken or concave portions on the rear sides of the tiles.

In accordance with a further development of the inventioin, in at least some of these recesses, locally widened channels are provided, which for example can serve for insertion of the separating or splitting tool for splitting the initial pair of tiles into the inidividual tiles or flags or can also serve, owing to their particuclar shape, for improving the anchoring of the tiles on their motar or adhesive bed.

DETAILED DESCRIPTION OF THE DRAWINGS Embodiments of the invention are now described with reference to the accompanying drawings.

FIG. 1 is a partial end view of a pair of split tiles before splitting, made in accordance with the invention;

FIG. 2 shows a knife-like core for the production of the recesses extending in the longitudinal direction of the split tiles illustrated in FIG. 1;

FIG. 3 shows a partial end view of a modified embodiment of the invention;

FIG. 4 is a fragmentary end view of an individual tile after being split from the pair of tiles illustrated in FIG. 3; and

FIG. 5 shows a further core for the production of recesses in a modified embodiment of the invention, similar to the embodiment shown in FIGS. 3 and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows the two tiles or flags 2 and 3 which are attached by means of connecting zones or necks 1. The connecting zones separate the sunken or concave portions 4 which are continuous in the longitudinal direction of the tile. The sunken portions 4 in cross section are approximately of sinusoidal shape in the construction shown. For the production of these sunken or concave portions in the extrusion nozzle, a knife-like core is provided which is shown in FIG. 2. This core produces convex or raised and concave or valley-like sunken portions on the back sides of the two tiles which are complementary to each other and, on separation of the two split tiles 2 and 3 of the pair along the plane AA, result in ribs which serve as anchoring attachments for the split tiles in their mortar or other adhesive bed. It will be seen that the fractured necks resulting from separation of the individual tiles are recessed well below the tops of the ribs of the tiles where they will not interfere with installation of the tile.

FIG. 3 shows a split tile pair 12, 13 with the tiles connected together by means of connecting zones or necks 11. The concave or sunken portions 14 are supplemented in this embodimennt by channels 15 which communicate with the opening separating the individual tiles and which receive the tip of the splitting tool in order to split the tile pair 12, 13 into the individual tiles.

It can be seen from FIG. 4 that the raised portions 16 and the sunken portions 17 produced are present together with the additional sunken or recessed portions formed by the channel 15. The channel forms a deep mortar or adhesive receiving groove in each of the individual tiles. Referene numeral 18 indicates the separation or fracture surfaces resulting at the connecting zones 11. From this Figure, it can be seen that the rough edges of flash produced on separation of the pair of split tiles never extend above the height of the raised portions 16. Again. the back face of the individual tiles is provided with alternating longitudinal ribs and valleys. The fracture zones resulting from separation of the individual tiles in both the forms illustrated in FIGS. 1 and 3 form steps in the sides ofthc valleys which steps have faces generally parallel to the front faces of the individual tiles.

FIG. 5 shows a core capable of producing the pattern in accordance with FIGS. 3 and 4 even though in a further modified form of this invention, the side flanks or walls of the raised portions 16 and the sunken portions 17 are so constructed as to have obliquely undercut or convergent side edges. It will be apparent to those in the art that the core is capable of doing this because the side limbs 19 of this core 20 are set in a suitably oblique manner. The Figure also indicates the additional part 21 of the core for the production of the generally keyshaped channel 15.

In accordance with the principal of the invention, it is naturally also possible to produce further forms of the sunken or valley portions so that the invention is not limited to the embodiments specifically shown.

The embodiments of the invention in which all exclusive property or privilege is claimed are obtained as follows:

I. In tiles of densely fired ceramic material formed in pairs arranged back to back with their back faces separated by a relatively thin channel extending lengthwise of the tiles, said channel at spaced points being interrupted by thin necks of material interconnecting the individual tiles, the improvement in said tiles compris ing: laterally of said tiles said channel being undulated and forming alternating ribs and valleys extending lengthwise of said tiles, said necks being located intermediate the tops of said ribs and the bottoms of said valleys whereby when said necks are fractured to separate said tiles no portion of the fractured necks projects above the tops of said ribs on either tile; a longitudinal slot in each of the individual tiles positioned intermediate said necks and communicating with said channel for receiving a splitting tool for separating the individual tiles and said slot in each individual tile providing a deep groove for receiving the bonding material used to install the tile.

2. Tiles as described'in claim 1 wherein the walls of said slots converge toward said channel to form a groove of undercut cross section.

3. Tiles as described in claim 1 wherein said necks when fractured form steps generally parallel to the front face of the individual tiles.

4. In tiles of densely fired ceramic material formed in pairs arranged back to back with their back faces separated by a relatively thin channel extending lengthwise of the tiles, said channel at spaced points being interrupted by thin necks of material interconnecting the individual tiles, the improvement in said tiles comprising: laterally of said tiles each of said channels in cross section having a straight central portion and oppositely projecting end portions extending at an acute angle to said central portion, said ends of adjacent ones of said channels being spaced to form said necks, the crosssectional plane of said central portion being inclined to the planes of the faces of said tiles whereby the ends of said channels and thereby said necks are arranged in a plane generally intermediate the thickest and thinnest portions of each of said tiles formed by said channels.

5. Tiles as described in claim 4 wherein a tool receiving opening communicates with at least one of said channels at an end of said tiles to facilitate separation of said tiles.

6. In tiles of densely fired ceramic material formed in pairs arranged back to back with their back faces separated by a relatively thin channel extending lengthwise of the tiles, said channel at spaced points being interrupted by thin necks of material interconnecting the individual tiles, the improvement in said tiles comprising: laterally of said tiles said channel being undulated and forming alternating ribs and valleys extending lengthwise of said tiles, said necks being located intermediate the tops of said ribs and the bottoms of said valleys whereby said necks are fractured to separate said tiles no portion of the fractured necks projects above the tops of said ribs on either tile; a tool opening in each of the individual tiles positioned intermediate a pair of said necks and communicating with said channel for receiving a splitting tool for separating the individual tiles.

7. Tiles as described in claim 6 wherein one of said tool openings is provided between each pair of said necks.

8. Tiles as described in claim 6 wherein one of said tool openings is provided at each end of said channel. l= l l 

1. IN TILES OF DENSELY FIRED CERAMIC MATERIAL FORMED IN PAIRS ARRANGED BACK TO BACK WITH THEIR BACK FACES SEPARATED BY A RELATIVELY THIN CHANNEL EXTENDING LENGTHWISE OF THE TILES, SAID CHANNEL AT SPACED POINTS BEING INTERRUPTED BY THIN NECKS OF MATERIAL INTERCONNECTING THE INDIVIDUAL TILES, THE IMPROVEMENT IN SAID TILES COMPRISING: LATERALLY OF SAID TILES SAID CHANNEL BEING UNDULATED AND FORMING ALTERNATING RIBS AND VALLEYS EXTENDING LENGTHWISE OF SAID TILES, SAID NECKS BEING LOCATED INTERMEDIATE THE TOPS OF SAID RIBS AND THE BOTTOMS OF SAID VALLEYS WHEREBY WHEN SAID NECKS ARE FRACTURED TO SEPARATE SAID TILES NO PORTION OF THE FRACTURED NECKS PROJECTS ABOVE THE TOPS OF SAID RIBS ON EITHER TILE; A LONGITUDINAL SLOT IN EACH OF THE INDIVIDUAL TILES POSITIONED INTERMEDIATE SAID NECKS AND COMMUNICATING WITH SAID CHANNEL FOR RECEIVING A SPLITTING TOOL FOR SEPARATING THE INDIVIDUAL TILES AND SAID SLOT IN EACH INDIVIDUAL TILE PROVIDING A DEEP GROOVE FOR RECEIVING THE BONDING MATERIAL USED TO INSTALL THE TILE.
 2. Tiles as described in claim 1 wherein the walls of said slots converge toward said channel to form a groove of undercut cross section.
 3. Tiles as described in claim 1 wherein said necks when fractured form steps generally parallel to the front face of the individual tiles.
 4. In tiles of densely fired ceramic material formed in pairs arranged back to back with their back faces separated by a relatively thin channel extending lengthwise of the tiles, said channel at spaced points being interrupted by thin necks of material interconnecting the individual tiles, the improvement in said tiles comprising: laterally of said tiles each of said channels in cross section having a straight central portion and oppositely projecting end portions extending at an acute angle to said central portion, said ends of adjacent ones of said channels being spaced to form said necks, the cross-sectional plane of said central portion being inclined to the planes of the faces of said tiles whereby the ends of said channels and thereby said necks are arranged in a plane generally intermediate the thickest and thinnest portions of each of said tiles formed by said channels.
 5. Tiles as described in claim 4 wherein a tool receiving opening communicates with at least one of said channels at an end of said tiles to facilitate separation of said tiles.
 6. In tiles of densely fired ceramic material formed in Pairs arranged back to back with their back faces separated by a relatively thin channel extending lengthwise of the tiles, said channel at spaced points being interrupted by thin necks of material interconnecting the individual tiles, the improvement in said tiles comprising: laterally of said tiles said channel being undulated and forming alternating ribs and valleys extending lengthwise of said tiles, said necks being located intermediate the tops of said ribs and the bottoms of said valleys whereby said necks are fractured to separate said tiles no portion of the fractured necks projects above the tops of said ribs on either tile; a tool opening in each of the individual tiles positioned intermediate a pair of said necks and communicating with said channel for receiving a splitting tool for separating the individual tiles.
 7. Tiles as described in claim 6 wherein one of said tool openings is provided between each pair of said necks.
 8. Tiles as described in claim 6 wherein one of said tool openings is provided at each end of said channel. 